The present study was undertaken to evaluate the improved protection of antegrade aortic root perfusion combined with intermittent coronary sinus occlusion(APCSO) for the 1-hour ischemic myocardium in the presence of left anterior descending artery occlusion. 12 dogs were divided into 2 groups: anteperfusion(AP) alone(n=6) and APCSO (n=6). The experimental results showed that APCSO provided a better cardioplegic distribution and a lower hypothermia (15.6°C versus 17.2°C) in the occluded LAD region, comrared with AP. After ischemia, cardiac index and left ventricular stroke index recovered excellently in APCSO (128% to 141% and 115% to 158% of preischemic values, respectively), and much worse in AP (69% to 82% and 53% to 73% of preischemic values, respectively). Our study has confirmed that APCSO is superior to AP in myocardial protection in the presence of coronary artery occlusion.
In order to investigate the feasibility of angiotensin converting enzyme inhibitors (ACEIs) in preventing the development of atherosclerosis and restenosis after coronary angioplasty and to study their mechanisms, we measured the platelet cytosilic free Ca2+ concentration ([Ca2+]i) and observed the effects of captopsil on platelet [Ca2+]i in rabbits and also observed the inhibitive action on fibroblast proliferation in culture. The results showed that resting platelet [Ca2+]i, ADPor thrombin-stimulated platelet elevation amplitude after administration of captopril (12.5 mg, twice daily) for 15 days were significantly reduced in comparison with those before administration. And captopril also significantly inhibited fibroblast proliferation or reduced3H-thymidine (3H-TdR) incorporation in culture in a dose-depdendent manner. These findings suggest that ACEIs are promising drugs to reduce restenosis incidence after coronary angioplasty and to prevent atherosclerosis as well as provide a new explanation for their effects of suppressing cell proliferation.